Variable Sized Arrays


Problem Statement :


Consider an n - element array, a, where each index i in the array a contains a reference to an array of  Ki integers (where the value Ki of varies from array to array). See the Explanation section below for a diagram.

Given a , you must answer q queries. Each query is in the format i j, where i denotes an index in array  a and j denotes an index in the array located at a[i] . For each query, find and print the value of element  j in the array at location a[i] on a new line.

Input Format

The first line contains two space-separated integers denoting the respective values of n (the number of variable-length arrays) and q (the number of queries). 

Each line i of n the subsequent lines contains a space-separated sequence in the format k a[i]0 a[i]1 … a[i]k-1 describing the k-element array located at a[i]. 

Each of the q subsequent lines contains two space-separated integers describing the respective values of i (an index in array ) and j (an index in the array referenced by a[i] ) for a query.

Constraints

1 <= n <= 10^5
1 <= q <= 10^5
1 <= k  <= 3 * 10^5
0 <= i  < n
0 <= j  < k

All indices in this challenge are zero-based.
All the given numbers are non negative and are not greater than  10^6.

Output Format

For each pair of i and j values (i.e., for each query), print a single integer that denotes the element located at index j of the array referenced by a[ i ]. There should be a total of q lines of output.



Solution :



title-img


                            Solution in C :

int n, q; cin >> n >> q;
    int **v = new int*[n];
    for(int j=0;j<n;j++){
        int k; cin >> k;
        v[j] = new int[k];
        for(int i=0;i<k;i++){
            int x; cin >> x;
            v[j][i] = x;
        }
    }
    for(int i=0;i<q;i++){
        int a, b; cin >> a >> b;
        cout << v[a][b]<<endl;
    }
	return 0;
}
                        








View More Similar Problems

Balanced Brackets

A bracket is considered to be any one of the following characters: (, ), {, }, [, or ]. Two brackets are considered to be a matched pair if the an opening bracket (i.e., (, [, or {) occurs to the left of a closing bracket (i.e., ), ], or }) of the exact same type. There are three types of matched pairs of brackets: [], {}, and (). A matching pair of brackets is not balanced if the set of bra

View Solution →

Equal Stacks

ou have three stacks of cylinders where each cylinder has the same diameter, but they may vary in height. You can change the height of a stack by removing and discarding its topmost cylinder any number of times. Find the maximum possible height of the stacks such that all of the stacks are exactly the same height. This means you must remove zero or more cylinders from the top of zero or more of

View Solution →

Game of Two Stacks

Alexa has two stacks of non-negative integers, stack A = [a0, a1, . . . , an-1 ] and stack B = [b0, b1, . . . , b m-1] where index 0 denotes the top of the stack. Alexa challenges Nick to play the following game: In each move, Nick can remove one integer from the top of either stack A or stack B. Nick keeps a running sum of the integers he removes from the two stacks. Nick is disqualified f

View Solution →

Largest Rectangle

Skyline Real Estate Developers is planning to demolish a number of old, unoccupied buildings and construct a shopping mall in their place. Your task is to find the largest solid area in which the mall can be constructed. There are a number of buildings in a certain two-dimensional landscape. Each building has a height, given by . If you join adjacent buildings, they will form a solid rectangle

View Solution →

Simple Text Editor

In this challenge, you must implement a simple text editor. Initially, your editor contains an empty string, S. You must perform Q operations of the following 4 types: 1. append(W) - Append W string to the end of S. 2 . delete( k ) - Delete the last k characters of S. 3 .print( k ) - Print the kth character of S. 4 . undo( ) - Undo the last (not previously undone) operation of type 1 or 2,

View Solution →

Poisonous Plants

There are a number of plants in a garden. Each of the plants has been treated with some amount of pesticide. After each day, if any plant has more pesticide than the plant on its left, being weaker than the left one, it dies. You are given the initial values of the pesticide in each of the plants. Determine the number of days after which no plant dies, i.e. the time after which there is no plan

View Solution →